Is it permissible to perform an obligatory prayer behind someone performing a voluntary prayer, such as tarawih?

Eid Abbasi : Is it permissible to perform an obligatory prayer behind someone who is praying a voluntary prayer, such as tarawih?

The Shaykh : Answer: Yes, based on the authentic hadith of Mu'adh ibn Jabal in "Sahih al-Bukhari," in which it is stated that he used to pray the obligatory 'Isha' prayer behind the Prophet (peace and blessings be upon him), and then he would go to the mosque of his neighborhood and lead them in prayer. It was a voluntary prayer for him and an obligatory prayer for them. Therefore, the prayer of a person who enters a mosque while the imam is praying tarawih is valid, provided that this person has not yet prayed the 'Isha' prayer. He must follow this imam. If he catches up with the imam for two rak'ahs, he should stand up and complete two rak'ahs. If he does not catch up with him, even if it is before the taslim, he should join him and then complete the four rak'ahs.